1. Field of the Invention
The invention relates to a multi-gear transmission device, in particular a two-gear transmission device, for transmitting a drive torque from an input side to an output side of the multi-gear transmission device, having at least two selectable gear ratios and a multi-stage clutch device, in particular a two-stage clutch device that has at least two different selectable limit torques.
2. Description of the Prior Art
Several different multi-gear transmission devices for power tools are already known. A multi-gear transmission device is in particular understood here to mean a transmission device that has at least two selectable gear ratios GR1 and GR2 between an input side of the transmission device and an output side of the transmission device. Each of the gear ratios is in particular understood here to be a gear of the multi-gear transmission device.
EP 1 163 980 A2, for example, has disclosed a two-gear transmission device that has two transmission gear pairs. Each of the transmission gear pairs here is composed of a first transmission gear and a second transmission gear. The transmission gears here are embodied in the form of spur wheels, in particular spur gears. Each of the transmission gear pairs has a different tooth ratio TR1, TR2 so that it is possible to implement different gear ratios GR1, GR2. The respective first transmission gears here are mounted on a first transmission shaft for co-rotation therewith. The second transmission gears are situated in rotary fashion on a hollow shaft functioning as a second transmission shaft. On the inside of the hollow shaft, a slider element is provided by means of which one of the two second transmission gears can be selectively connected to the hollow shaft for co-rotation therewith. At one end of the hollow shaft, a bevel pinion is provided, which meshes with a bevel disc wheel. The bevel disc wheel in this case is mounted on a rotatably supported tool drive shaft, in particular a hammer tube, in a co-rotational fashion. The larger of the first transmission gears meshes with a spur pinion that is provided on a motor shaft of a drive unit, in particular an electric motor. The first transmission gears thus define an input side of the multi-gear transmission device, while the second transmission gears define an output side of the multi-gear transmission device. A drive torque MA of the drive unit is then transmitted to the tool drive shaft by means of the selectable co-rotation connection of one of the two second transmission gears to the hollow shaft.
There are also known transmission devices that include a multi-stage clutch device, in particular a two-stage clutch device. The multi-stage clutch devices in this case have at least two different selectable limit torques MG1, MG2 acting between an input side of the transmission device and an output side of the transmission device. If the currently applied drive torque MA exceeds the currently selected limit torque MGIst, then the multi-stage clutch device interrupts the torque transmission between the input side and the output side.
DE 38 32 202 C1, for example, has disclosed a two-stage clutch device that has two coupleable overload clutches arranged in series on a clutch shaft. The overload clutches in this case are selectively connected to each other and/or immobilized relative to a housing by means of a switchable, axially movable pin that is situated in a radially outer region of the overload clutch. As a result, depending on the switching position of the pin, two different limit torques MG1, MG2 are operative in relation to the clutch shaft.